Assign version to backend

central_backend/src/server/web_api/server_controller.rs

@@ -13,6 +13,7 @@ struct ServerConfig {
     auth_disabled: bool,
     constraints: StaticConstraints,
     unsecure_origin: String,
+    backend_version: &'static str,
 }
 
 impl Default for ServerConfig {
@@ -21,6 +22,7 @@ impl Default for ServerConfig {
             auth_disabled: AppConfig::get().unsecure_disable_login,
             constraints: Default::default(),
             unsecure_origin: AppConfig::get().unsecure_origin(),
+            backend_version: env!("CARGO_PKG_VERSION"),
         }
     }
 }